Gas turbine combustor

ABSTRACT

A combustor of an embodiment includes: a combustor casing; a combustor liner which is provided in the combustor casing and combusts a fuel and an oxidant to produce a combustion gas; a pipe-shaped member provided to penetrate the combustor casing and the combustor liner; a heat-resistant glass which is provided on the combustor casing side in the pipe-shaped member and closes the pipe-shaped member; a laser light supply mechanism which irradiates an interior of the combustor liner through the heat-resistant glass and an interior of the pipe-shaped member with a laser light; and a contact prevention mechanism which prevents a combustion gas in the combustor liner from coming into contact with the heat-resistant glass.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 17/165,147, filed on Feb. 2, 2021, which is based upon andclaims the benefit of priority from Japanese Patent Application No.2020-020881, filed on Feb. 10, 2020; the entire contents of which areincorporated herein by reference.

FIELD

Embodiments described herein relate generally to a gas turbinecombustor.

BACKGROUND

Increasing the efficiency of power generation plants is in progress inresponse to demands for reduction of carbon dioxide, resourceconservation, and the like. Specifically, increasing the temperature ofa working fluid of a gas turbine, employing a combined cycle, and thelike are actively in progress. Further, research and development ofcollection techniques of carbon dioxide are also in progress.

Under such circumstances, a gas turbine facility including a combustorwhich combusts a fuel and oxygen in a supercritical CO₂ atmosphere (tobe referred to as a CO₂ gas turbine facility, hereinafter) is underconsideration. In this CO₂ gas turbine facility, a part of a combustiongas produced in the combustor is circulated in a system as a workingfluid.

Therefore, in the CO₂ gas turbine facility, excess oxygen and fuelpreferably do not remain in the combustion gas discharged from thecombustor. Thus, flow rates of the fuel and an oxidant are regulated soas to have a stoichiometric mixture ratio (equivalence ratio 1), forexample.

Incidentally, the equivalence ratio which is mentioned here is anequivalence ratio calculated based on a fuel flow rate and an oxygenflow rate. In other words, it is an equivalence ratio when it is assumedthat the fuel and the oxygen are uniformly mixed (overall equivalenceratio).

In the combustor of the CO₂ gas turbine facility, a fuel-oxidant mixturemixed in the combustor is ignited by using an ignition device. Atpresent, as the ignition device included in the combustor of the CO₂ gasturbine facility, a laser spark ignition device is under consideration.The laser ignition device irradiates the mixture inside the combustorwith laser light to cause ignition.

The laser spark ignition device includes a laser oscillator, a lens, aheat-resistant glass provided in a casing part, and a laser passage pipecoupling a casing and a combustor liner, for example. Then, the interiorof the combustor liner is irradiated through the lens, theheat-resistant glass, and the laser passage pipe with laser lightemitted from the laser oscillator.

Then, the laser light is focused in the combustor liner. By the laserlight being focused, an energy density increases. Then, gas in theportion where the energy density increases is plasmatized (breaks down)to ignite the mixture.

In the above-described laser ignition device of the CO₂ gas turbinefacility, the combustion gas sometimes flows into the laser passagepipe. Then, an inner surface of the heat-resistant glass is exposed tothe combustion gas and impurities such as soot adhere to the innersurface of the heat-resistant glass in some cases. This sometimes causesa reduction in transmittance of the laser light passing through theheat-resistant glass, resulting in not enabling stable ignition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a system diagram of a gas turbine facility including acombustor of a first embodiment.

FIG. 2 is a view schematically illustrating a longitudinal section ofthe combustor of the first embodiment.

FIG. 3 is an enlarged view schematically illustrating a longitudinalsection of an ignition device in the combustor of the first embodiment.

FIG. 4 is an enlarged view schematically illustrating a longitudinalsection of the ignition device including another configuration in thecombustor of the first embodiment.

FIG. 5 is a view schematically illustrating a longitudinal section of acombustor of a second embodiment.

FIG. 6 is an enlarged view schematically illustrating a longitudinalsection of an ignition device in the combustor of the second embodiment.

FIG. 7 is an enlarged view schematically illustrating a longitudinalsection of an ignition device in a combustor of a third embodiment.

FIG. 8 is an enlarged view schematically illustrating a longitudinalsection of the ignition device including another configuration in thecombustor of the third embodiment.

FIG. 9 is an enlarged view schematically illustrating a longitudinalsection of an ignition device in a combustor of a fourth embodiment.

FIG. 10 is an enlarged view schematically illustrating a longitudinalsection of an ignition device in a combustor of a fifth embodiment.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present invention will be described withreference to the drawings.

In one embodiment, a gas turbine combustor includes: a casing; acombustion cylinder which is provided in the casing and combusts a fueland an oxidant to produce a combustion gas; a pipe-shaped memberprovided to penetrate the casing and the combustion cylinder; aheat-resistant glass which is provided on the casing side in thepipe-shaped member and closes the pipe-shaped member; a laser lightsupply mechanism which irradiates an interior of the combustion cylinderthrough the heat-resistant glass and an interior of the pipe-shapedmember with a laser light; and a contact prevention mechanism whichprevents a combustion gas in the combustion cylinder from coming intocontact with the heat-resistant glass.

First Embodiment

FIG. 1 is a system diagram of a gas turbine facility 10 including acombustor 20A of a first embodiment. As illustrated in FIG. 1 , the gasturbine facility 10 includes the combustor 20A which combusts a fuel andan oxidant, a pipe 40 which supplies the fuel to the combustor 20A, anda pipe 41 which supplies the oxidant to the combustor 20A. Further, thecombustor 20A includes an ignition device 100A which ignites a mixtureof the fuel and the oxidant in the combustor 20A. Note that thecombustor 20A functions as a gas turbine combustor.

The pipe 40 includes a flow rate regulating valve 21 which regulates aflow rate of the fuel to be supplied into a combustor liner 61 of thecombustor 20A. Here, as the fuel, for example, hydrocarbon such asmethane or natural gas is used. Further, as the fuel, for example, acoal gasification gas fuel containing carbon monoxide, hydrogen, and thelike can also be used. Note that the combustor liner 61 functions as acombustion cylinder.

The pipe 41 is provided with a compressor 23 which pressurizes theoxidant. As the oxidant, for example, oxygen separated from theatmosphere by an air separating apparatus (not illustrated) is used. Theoxidant flowing through the pipe 41 is heated by passing through a heatexchanger 24 to be supplied to the combustor 20A.

The fuel and the oxidant guided to the combustor liner 61 undergoreaction (combustion) in a combustion region in the combustor liner 61and are turned into a combustion gas. Here, in the gas turbine facility10, a part of the combustion gas exhausted from a turbine 25 iscirculated in the system, which is described later. Therefore, excessoxidant (oxygen) and fuel preferably do not remain in the combustion gasdischarged from the combustor liner 61.

Thus, flow rates of the fuel and the oxidant are regulated so as to havea stoichiometric mixture ratio (equivalence ratio 1), for example. Notethat the equivalence ratio mentioned here is an equivalence ratio(overall equivalence ratio) when it is assumed that the fuel and theoxygen are uniformly mixed.

Further, the gas turbine facility 10 includes a turbine 25, a generator26, a heat exchanger 24, a cooler 27, and a compressor 28. Moreover, thegas turbine facility 10 includes a pipe 42 for circulating a part of thecombustion gas discharged from the turbine 25 in the system.

The turbine 25 is moved rotationally by the combustion gas dischargedfrom the combustor liner 61. To the turbine 25, for example, thegenerator 26 is coupled. The combustion gas discharged from thecombustor liner 61, which is mentioned here, is one containing acombustion product produced from the fuel and the oxidant and carbondioxide to be circulated in the combustor liner 61 (a combustion gasfrom which water vapor has been removed).

The combustion gas discharged from the turbine 25 is guided to the pipe42 and cooled by passing through the heat exchanger 24. At this time,the oxidant flowing through the pipe 41 and carbon dioxide flowingthrough the pipe 42 to be circulated through the combustor 20A areheated by heat release from the combustion gas.

The combustion gas having passed through the heat exchanger 24 passesthrough the cooler 27. By the combustion gas passing through the cooler27, the water vapor contained in the combustion gas is removedtherefrom. At this time, the water vapor in the combustion gas condensesinto water. This water is discharged through a pipe 43 to the outside,for example.

Here, as described previously, when the flow rates of the fuel and theoxidant are regulated so as to have the stoichiometric mixture ratio(equivalence ratio 1), most of components of the combustion gas (drycombustion gas) from which the water vapor has been removed are carbondioxide. Note that, for example, a slight amount of carbon monoxide, orthe like is sometimes mixed in the combustion gas from which the watervapor has been removed, but hereinafter, the combustion gas from whichthe water vapor has been removed is simply referred to as carbondioxide.

The carbon dioxide is pressurized to a pressure equal to or more than acritical pressure by the compressor 28 interposed in the pipe 42 tobecome a supercritical fluid. A part of the pressurized carbon dioxideflows through the pipe 42 and is heated in the heat exchanger 24. Then,the carbon dioxide is guided between the combustor liner 61 and acylinder body 80. The temperature of the carbon dioxide having passedthrough the heat exchanger 24 becomes, for example, about 700° C. Notethat the pipe 42 which supplies carbon dioxide between the combustorliner 61 and the cylinder body 80 also functions as a first fluid supplypart.

Another part of the pressurized carbon dioxide is introduced to a pipe44 branching off from the pipe 42, for example. The carbon dioxideintroduced to the pipe 44 is guided between a combustor casing 70 andthe cylinder body 80 as a cooling medium after its flow rate isregulated by a flow rate regulating valve 29. The temperature of thecarbon dioxide guided between the combustor casing 70 and the cylinderbody 80 by the pipe 44 is, for example, about 400° C.

This temperature of the carbon dioxide guided between the combustorcasing 70 and the cylinder body 80 is lower than thepreviously-described temperature of the carbon dioxide guided betweenthe combustor liner 61 and the cylinder body 80. Note that the pipe 44which supplies the carbon dioxide between the combustor casing 70 andthe cylinder body 80 also functions as a first fluid supply part.Further, the combustor casing 70 functions as a casing.

Meanwhile, further another part of the pressurized carbon dioxide isintroduced to a pipe 45 branching off from the pipe 42. The carbondioxide introduced to the pipe 45 is discharged to the outside after itsflow rate is regulated by a flow rate regulating valve 30. Note that thepipe 45 functions as a discharge pipe. The carbon dioxide discharged tothe outside can be utilized for EOR (Enhanced Oil Recovery) or the likeemployed at an oil drilling field, for example.

Next, a configuration of the combustor 20A of the first embodiment isdescribed in detail.

FIG. 2 is a view schematically illustrating a longitudinal section ofthe combustor 20A of the first embodiment. FIG. 3 is an enlarged viewschematically illustrating a longitudinal section of the ignition device100A in the combustor 20A of the first embodiment.

As illustrated in FIG. 2 , the combustor 20A includes a fuel nozzle part60, the combustor liner 61, a transition piece 62, the combustor casing70, the cylinder body 80, and the ignition device 100A.

The fuel nozzle part 60 ejects the fuel supplied from the pipe 40 andthe oxidant supplied from the pipe 41 into the combustor liner 61. Forexample, the fuel is ejected from the center and the oxidant is ejectedfrom the periphery of the center.

The combustor casing 70 is provided along a longitudinal direction ofthe combustor 20A so as to surround a part of the fuel nozzle part 60,the combustor liner 61, and the transition piece 62, for example. Thecombustor casing 70 is divided into two parts in the longitudinaldirection of the combustor 20A, for example. The combustor casing 70 isconstituted of an upstream-side casing 71 on an upstream side and adownstream-side casing 72 on a downstream side, for example.

The upstream-side casing 71 is constituted by a cylinder body having oneend (upstream end) thereof closed and the other end (downstream end)thereof opened, for example. In the center of the one end, an opening 71a into which the fuel nozzle part 60 is inserted is formed. Further, thepipe 44 is coupled to a side portion of the upstream-side casing 71. Thepipe 44 is fitted in and joined to an opening 71 b formed in the sideportion of the upstream-side casing 71, for example.

The downstream-side casing 72 is constituted by a cylinder body havingboth ends thereof opened. One end of the downstream-side casing 72 isconnected to the upstream-side casing 71. The other end of thedownstream-side casing 72 is connected to, for example, a casingsurrounding the turbine 25.

As illustrated in FIG. 2 , in the combustor casing 70, the cylinder body80 which surrounds peripheries of a part of the fuel nozzle part 60, thecombustor liner 61, and the transition piece 62 and demarcates a spacebetween the combustor casing 70 and the combustor liner 61 is provided.Predetermined spaces exist between the combustor liner 61 and thecylinder body 80 and between the combustor casing 70 and the cylinderbody 80.

The cylinder body 80 has one end (upstream end) thereof closed, in whichan opening 81 into which the fuel nozzle part 60 is inserted is formed.The cylinder body 80 has the other end (downstream end) thereof closed,in which an opening 82 through which a downstream end of the transitionpiece 62 penetrates is formed. The cylinder body 80 is formed by joininga plate-shaped lid member 80 a having the opening 81 therein to acylindrical main body member 80 b, for example.

A configuration of the cylinder body 80 is not limited as long as thecylinder body 80 has a structure which surrounds the peripheries of apart of the fuel nozzle part 60, the combustor liner 61, and thetransition piece 62 as illustrated in FIG. 2 .

An inner peripheral surface of the downstream-side opening 82 in thecylinder body 80 is in contact with an outer peripheral surface of thedownstream end portion of the transition piece 62.

Further, the pipe 42 is coupled to an upstream-side side portion of thecylinder body 80. The pipe 42 is coupled to the side portion of thecylinder body 80 by passing through the interior of the pipe 44 coupledto the side portion of the upstream-side casing 71, as illustrated inFIG. 2 , for example. The pipe 44 and the pipe 42 passes through theinterior of the pipe 44 form a double-pipe structure.

Incidentally, the pipe 42 is inserted through an opening 44 a formed inthe pipe 44 into the interior of the pipe 44, for example. Then, thepipe 42 is joined to the pipe 44 in an opening portion having theopening 44 a, for example. Further, the double-pipe structure of thepipe 42 and the pipe 44 is not limited to being provided at one placeand may be plurally provided in a circumferential direction.

The ignition device 100A includes a pipe-shaped member 101, aheat-resistant glass 102, a laser light supply mechanism 103, and acontact prevention mechanism 104A as illustrated in FIG. 2 and FIG. 3 .

The pipe-shaped member 101 is constituted by a cylindrical pipe havingboth ends thereof opened, or the like. The pipe-shaped member 101 isprovided to penetrate the combustor casing 70, the cylinder body 80, andthe combustor liner 61. In other words, the pipe-shaped member 101 isdisposed so as to penetrate through a coaxial circular communicationhole (through hole) formed in each of the combustor casing 70, thecylinder body 80, and the combustor liner 61 from the directionperpendicular to the longitudinal direction of the combustor 20A.

Incidentally, an inner end portion 101 a of the pipe-shaped member 101is configured not to project to the interior of the combustor liner 61.Further, an inside diameter of the pipe-shaped member 101 is set to theextent that laser light is not hindered when it passes through theinterior of the pipe-shaped member 101.

The heat-resistant glass 102 is provided on the outer side (combustorcasing 70 side) in the pipe-shaped member 101. Specifically, theheat-resistant glass 102 is preferably provided in the pipe-shapedmember 101 on a side close to the outside than a flow path between thecombustor casing 70 and the cylinder body 80, through which the carbondioxide flows. For example, the heat-resistant glass 102 is provided onan outer end portion 101 b side of the pipe-shaped member 101.

The heat-resistant glass 102 is provided so as to close the interior ofthe pipe-shaped member 101. This shuts off communication between theinside and the outside of the combustor 20A.

The laser light supply mechanism 103 irradiates the interior of thecombustor liner 61 through the heat-resistant glass 102 and the interiorof the pipe-shaped member 101 with a laser light 110. The laser lightsupply mechanism 103 includes a laser oscillator 103 a and a condensinglens 103 b.

The condensing lens 103 b is provided outside the combustor casing 70(downstream-side casing 72) to face the heat-resistant glass 102. Thatis, the condensing lens 103 b is provided between the laser oscillator103 a and the heat-resistant glass 102. A focal length and aninstallation position of the condensing lens 103 b are set so as to havea focal point 11 a at a position suitable for igniting the fuel-airmixture.

The laser oscillator 103 a is disposed outside the combustor casing 70.The laser oscillator 103 a irradiates the interior of the combustorliner 61 through the condensing lens 103 b, the heat-resistant glass102, and the interior of the pipe-shaped member 101 with the laser light110. That is, the laser oscillator 103 a is disposed so as to be able toirradiate the interior of the combustor liner 61 with the laser light110 by passing the laser light 110 through the condensing lens 103 b,the heat-resistant glass 102, and the interior of the pipe-shaped member101 in this order.

Incidentally, the condensing lens 103 b may be irradiated through anoptical fiber with the laser light 110 oscillated by the laseroscillator 103 a.

The contact prevention mechanism 104A prevents the combustion gas in thecombustor liner 61 from coming into contact with the heat-resistantglass 102. The contact prevention mechanism 104A includes a fluid supplypart 120 and an ejection part 130.

The fluid supply part 120 supplies a fluid for preventing the contactbetween the combustion gas in the combustor liner 61 and theheat-resistant glass 102. Note that the fluid for preventing the contactbetween the combustion gas in the combustor liner 61 and theheat-resistant glass 102 is hereinafter referred to as a contactprevention fluid.

The fluid supply part 120 supplies the contact prevention fluid betweenthe combustor casing 70 and the combustor liner 61. Here, specifically,the fluid supply part 120 supplies the contact prevention fluid betweenthe combustor liner 61 and the cylinder body 80.

Here, the fluid supply part 120 is constituted of the pipe 42 whichcirculates the carbon dioxide heated in the heat exchanger 24 betweenthe combustor liner 61 and the cylinder body 80. Note that, the fluidsupply part 120 functions as the first fluid supply part, and thecontact prevention fluid to be supplied by the fluid supply part 120functions as a first fluid.

Further, the carbon dioxide supplied between the combustor liner 61 andthe cylinder body 80 also functions as a cooling medium to cool thecombustor liner 61 and the transition piece 62 other than the functionas the contact prevention fluid.

The ejection part 130 ejects the contact prevention fluid into thepipe-shaped member 101. The ejection part 130 has a plurality ofejection holes 131 formed in a circumferential direction of thepipe-shaped member 101.

The ejection part 130 is formed in the pipe-shaped member 101 locatedbetween the combustor liner 61 and the cylinder body 80, for example. Inother words, the ejection holes 131 are formed in the circumferentialdirection of the pipe-shaped member 101 located between the combustorliner 61 and the cylinder body 80.

The ejection hole 131 is constituted by a circular hole, a slit, or thelike. Further, the ejection holes 131 are disposed uniformly in thecircumferential direction of the pipe-shaped member 101. The ejectionholes 131 each penetrate in a direction perpendicular to a center axisof the pipe-shaped member 101, for example.

Here, a pressure of the contact prevention fluid to be ejected into thepipe-shaped member 101 is higher than a pressure in the combustor liner61. Therefore, the combustion gas flowing into the pipe-shaped member101 does not pass through the ejection holes 131 to flow in between thecombustor liner 61 and the cylinder body 80. In other words, the contactprevention fluid ejected from the ejection holes 131 into thepipe-shaped member 101 flows into the combustor liner 61.

Next, the operation of the combustor 20A is described.

At the time of ignition, the laser oscillator 103 a is driven tooscillate the laser light 110. The laser light 110 oscillated by thelaser oscillator 103 a passes through the condensing lens 103 b and theheat-resistant glass 102 to enter the pipe-shaped member 101. The laserlight 110 having passed through the interior of the pipe-shaped member101 is focused on the focal point 110 a in a predetermined region in thecombustor liner 61. Note that the laser light 110 travels from the focalpoint 110 a in a traveling direction while expanding a beam diameter.

After the irradiation of the interior of the combustor liner 61 with thelaser light 110, the fuel and the oxygen are ejected from the fuelnozzle part 60 into the combustor liner 61. At this time, the fuel andthe oxygen are ejected from the fuel nozzle part 60 in a state of theoxidant flow rate and the fuel flow rate being reduced in order tosuppress a sudden heat load on the combustor 20A.

The oxidant and the fuel ejected from the fuel nozzle part 60 flow whilemixing together to create a mixture. Then, when the mixture flows to ahigh energy density position where the laser light is focused on thefocal point 110 a, the mixture is ignited. This initiates combustion.Note that drive of the ignition device 100A is stopped when thecombustion in the combustor liner 61 is stabilized, for example.

Then, after the ignition, the flow rate of the circulating carbondioxide and the oxidant flow rate are increased to increase the pressurein the combustor, and at the same time, the fuel flow rate is increasedto increase the combustion gas temperature in the combustor. Then, thefuel flow rate, the flow rate of the circulating carbon dioxide, and theoxidant flow rate are increased up to a rated load condition of theturbine.

Since the action of the combustion gas discharged from the combustorliner 61 has been already described with reference to FIG. 1 , flows ofthe carbon dioxide introduced from the pipe 42 and the pipe 44 into thecombustor 20A are described here with reference to FIG. 2 and FIG. 3 .

A part of the carbon dioxide introduced from the pipe 42 into thecylinder body 80 functions as the contact prevention fluid. Asillustrated in FIG. 3 , a part of the carbon dioxide passes through theejection holes 131 of the pipe-shaped member 101 to be ejected into thepipe-shaped member 101. Note that in FIG. 3 , flows of the contactprevention fluid (carbon dioxide) ejected from the ejection holes 131are indicated by arrows.

The flows of the contact prevention fluid (carbon dioxide) ejected fromthe ejection holes 131 each travel in the direction perpendicular to thecenter axis of the pipe-shaped member 101, and at the same time, turn tothe combustor liner 61 side, as illustrated in FIG. 3 , for example.That is, in the pipe-shaped member 101, a flow field toward the interiorof the combustor liner 61 is formed by the contact prevention fluidejected from the ejection holes 131.

Further, in the interior of the pipe-shaped member 101 being an innerside of the ejection holes 131, such a flow field as to shut off a crosssection of the interior of the pipe-shaped member 101 is formed by thecontact prevention fluid ejected from the plurality of ejection holes131 formed in the circumferential direction.

Here, the contact prevention fluid to be ejected from the ejection holes131 preferably has a penetration force to the extent of being capable ofreaching the vicinity of the center axis of the pipe-shaped member 101.Specifically, the contact prevention fluid to be ejected from theejection holes 131 preferably has a penetration force to the extent ofcoming into contact with an outer periphery of the laser light 110(laser beam) passing through the center of the pipe-shaped member 101,for example.

The above-described flows formed by the contact prevention fluid ejectedfrom the ejection holes 131 prevent the combustion gas in the combustorliner 61 from flowing into the pipe-shaped member 101. Alternatively,the flows formed by the contact prevention fluid ejected from theejection holes 131 prevent the combustion gas flowing from the interiorof the combustor liner 61 into the pipe-shaped member 101 from flowinginto the side closer to the heat-resistant glass 102 from positionsformed with the ejection holes 131.

This makes it possible to prevent the combustion gas in the combustorliner 61 from coming into contact with the heat-resistant glass 102 (aninner surface 102 a of the heat-resistant glass 102). Then, impuritiessuch as soot contained in the combustion gas do not adhere to the innersurface 102 a of the heat-resistant glass 102. Therefore, it is possibleto prevent a reduction in transmittance of the laser light 110 passingthrough the heat-resistant glass 102.

Incidentally, the contact prevention fluid ejected from the ejectionholes 131 into the pipe-shaped member 101 flows into the combustor liner61. The contact prevention fluid flowing into the combustor liner 61 isintroduced into the transition piece 62 together with the combustiongas.

Here, a flow rate of the contact prevention fluid to be ejected to thepipe-shaped member 101 can be regulated by a hole diameter of theejection hole 131 and the number of the ejection holes 131. The flowrate of the contact prevention fluid to be ejected from the ejectionholes 131 into the pipe-shaped member 101 is preferably a minimum flowrate which can prevent inflow of the combustion gas to theheat-resistant glass 102 side.

This allows flames to be formed in the combustor liner 61 without beingaffected by the contact prevention fluid flowing from the pipe-shapedmember 101 into the combustor liner 61.

On one hand, the remaining part of the carbon dioxide introduced fromthe pipe 42 into the cylinder body 80 flows through an annular spacebetween the combustor liner 61 and the cylinder body 80 to thedownstream side. At this time, the carbon dioxide cools the combustorliner 61 and the transition piece 62.

Then, the carbon dioxide is introduced from, for example, holes 63, 64of a porous film cooling part, dilution holes 65, and the like in thecombustor liner 61 and the transition piece 62 into the combustor liner61 and the transition piece 62. The carbon dioxide introduced into thecombustor liner 61 and the transition piece 62 is introduced to theturbine 25 together with the combustion gas produced by the combustion.

As illustrated in FIG. 2 , the low-temperature carbon dioxide flowingthrough the pipe 44 is guided to a double pipe constituted by the pipe42 and the pipe 44. The carbon dioxide guided to the double pipe passesthrough an annular passage between the pipe 42 and the pipe 44 to beguided between the combustor casing 70 and the cylinder body 80.

The carbon dioxide guided between the combustor casing 70 and thecylinder body 80 flows through the annular space between the combustorcasing 70 and the cylinder body 80 to the downstream side. At this time,the carbon dioxide cools the combustor casing 70, the cylinder body 80,and the pipe-shaped member 101 of the ignition device 100A. This carbondioxide is used also for cooling stator blades 85 and rotor blades 86 ofthe turbine 25, for example. By such cooling, the temperature of thecombustor casing 70 becomes, for example, about 400° C.

Therefore, it is possible to maintain the temperature of the combustorcasing 70 with the heat-resistant glass 102 of the ignition device 100Ainstalled therein to about 400° C. even at the time of the turbine ratedload of the CO₂ gas turbine facility. That is, the temperature of theheat-resistant glass 102 of the ignition device 100A is maintained toabout 400° C.

According to the combustor 20A of the first embodiment as describedabove, including the contact prevention mechanism 104A makes it possibleto prevent the contact between the heat-resistant glass 102 included inthe pipe-shaped member 101 of the ignition device 100A and thecombustion gas. Therefore, the impurities such as soot do not adhere tothe inner surface 102 a of the heat-resistant glass 102. This preventsthe reduction in transmittance of the laser light 110 passing throughthe heat-resistant glass 102, resulting in enabling stable ignition.

Here, in the above-described embodiment, one example of the ejectionholes 131 each penetrating in the direction perpendicular to the centeraxis of the pipe-shaped member 101 is indicated, but a configuration ofthe ejection hole 131 is not limited to this.

FIG. 4 is an enlarged view schematically illustrating a longitudinalsection of the ignition device 100A including another configuration inthe combustor 20A of the first embodiment.

As illustrated in FIG. 4 , ejection holes 131 may each be formed to beinclined to the end portion 101 a side of the pipe-shaped member 101relative to the direction perpendicular to the center axis of thepipe-shaped member 101. That is, the ejection holes 131 may each beformed to be inclined so that an outlet of the ejection hole 131 islocated closer to the end portion 101 a side of the pipe-shaped member101 than an inlet of the ejection hole 131.

In this case, the contact prevention fluid ejected from the ejectionholes 131 has a component of velocity along the center axis of thepipe-shaped member 101. This makes it likely to form a flow field of thecontact prevention fluid having a penetration force to the extent ofcoming into contact with an outer periphery of the laser light 110(laser beam) passing through the center of the pipe-shaped member 101.Then, the interior of the combustor liner 61 is irradiated with thelaser light 110 in a state of suppressing an influence from the contactprevention fluid.

Second Embodiment

FIG. 5 is a view schematically illustrating a longitudinal section of acombustor 20B of a second embodiment. FIG. 6 is an enlarged viewschematically illustrating a longitudinal section of an ignition device100B in the combustor 20B of the second embodiment. Note that in thefollowing embodiment, the same constituent portions as those of thecombustor 20A of the first embodiment are denoted by the same referencesigns, and redundant explanations are omitted or simplified.

The combustor 20B of the second embodiment has the same configuration asthat of the combustor 20A of the first embodiment except a configurationof a contact prevention mechanism 104B of the ignition device 100B.Therefore, the configuration of the contact prevention mechanism 104B ismainly described here.

As illustrated in FIG. 5 , the ignition device 100B includes apipe-shaped member 101, a heat-resistant glass 102, a laser light supplymechanism 103, and the contact prevention mechanism 104B.

The contact prevention mechanism 104B prevents a combustion gas in acombustor liner 61 from coming into contact with the heat-resistantglass 102. The contact prevention mechanism 104B includes a fluid supplypart 140 and an ejection part 150.

The fluid supply part 140 supplies a contact prevention fluid. The fluidsupply part 140 supplies the contact prevention fluid between acombustor casing 70 and a cylinder body 80.

Here, the fluid supply part 140 is constituted of a pipe 44 whichcirculates the carbon dioxide pressurized by the compressor 28 betweenthe combustor casing 70 and the cylinder body 80. Here, the carbondioxide circulated by the pipe 44 is not heated in the heat exchanger24.

Incidentally, the fluid supply part 140 functions as a first fluidsupply part, and the contact prevention fluid to be supplied by thefluid supply part 140 functions as a first fluid.

Further, the carbon dioxide supplied between the combustor casing 70 andthe cylinder body 80 also functions as a cooling medium to cool thecombustor casing 70, the cylinder body 80 and the pipe-shaped member 101of the ignition device 100B other than the function as the contactprevention fluid.

The ejection part 150 ejects the contact prevention fluid into thepipe-shaped member 101. The ejection part 150 has a plurality ofejection holes 151 formed in a circumferential direction of thepipe-shaped member 101.

The ejection part 150 is formed in the pipe-shaped member 101 locatedbetween the combustor casing 70 and the cylinder body 80, for example.In other words, the ejection holes 151 are formed in the circumferentialdirection of the pipe-shaped member 101 located between the combustorcasing 70 and the cylinder body 80.

A shape and a disposition configuration of the ejection holes 151 arethe same as those of the ejection holes 131 of the first embodiment.Further, the ejection holes 151 each penetrate in a directionperpendicular to a center axis of the pipe-shaped member 101, forexample.

Incidentally, as exemplified by the first embodiment (refer to FIG. 4 ),the ejection holes 151 may each be formed to be inclined to an endportion 101 a side of the pipe-shaped member 101 relative to thedirection perpendicular to the center axis of the pipe-shaped member101. An effect obtained by the above is the same as the effect describedby the first embodiment.

Here, a pressure of the contact prevention fluid to be ejected into thepipe-shaped member 101 is higher than a pressure in the combustor liner61. Therefore, the combustion gas flowing into the pipe-shaped member101 does not pass through the ejection holes 151 to flow in between thecombustor casing 70 and the cylinder body 80. In other words, thecontact prevention fluid ejected from the ejection holes 151 into thepipe-shaped member 101 flows into the combustor liner 61.

Next, the operation of the combustor 20B is described.

Here, the operation of the contact prevention mechanism 104B isdescribed.

A part of the carbon dioxide introduced between the combustor casing 70and the cylinder body 80 from the pipe 44 functions as the contactprevention fluid. As illustrated in FIG. 6 , a part of the carbondioxide passes through the ejection holes 151 of the pipe-shaped member101 to be ejected into the pipe-shaped member 101. Note that in FIG. 6 ,flows of the carbon dioxide (contact prevention fluid) ejected from theejection holes 151 are indicated by arrows.

The flows of the carbon dioxide (contact prevention fluid) ejected fromthe ejection holes 151 are similar to the flows of the carbon dioxide(contact prevention fluid) ejected from the ejection holes 131 in thefirst embodiment. That is, the flows of the carbon dioxide (contactprevention fluid) ejected from the ejection holes 151 each travel in thedirection perpendicular to the center axis of the pipe-shaped member101, and at the same time, turn to the combustor liner 61 side, asillustrated in FIG. 6 , for example.

Further, in the interior of the pipe-shaped member 101 being an innerside of the ejection holes 151, such a flow field as to shut off a crosssection of the interior of the pipe-shaped member 101 is formed by thecarbon dioxide ejected from the plurality of ejection holes 151 formedin the circumferential direction.

The flows formed by the carbon dioxide ejected from the ejection holes151 prevent the combustion gas in the combustor liner 61 from flowinginto the pipe-shaped member 101. Alternatively, the flows formed by thecarbon dioxide ejected from the ejection holes 151 prevent thecombustion gas flowing from the interior of the combustor liner 61 intothe pipe-shaped member 101 from flowing into the side closer to theheat-resistant glass 102 from positions formed with the ejection holes151.

This makes it possible to prevent the combustion gas in the combustorliner 61 from coming into contact with the heat-resistant glass 102 (aninner surface 102 a of the heat-resistant glass 102). Then, impuritiessuch as soot contained in the combustion gas do not adhere to the innersurface 102 a of the heat-resistant glass 102. Therefore, it is possibleto prevent a reduction in transmittance of the laser light 110 passingthrough the heat-resistant glass 102.

Incidentally, similarly to the first embodiment, a flow rate of thecontact prevention fluid to be ejected to the pipe-shaped member 101 canbe regulated by a hole diameter of the ejection hole 151 and the numberof the ejection holes 151. An effect obtained by the above is also thesame as that of the first embodiment.

On one hand, the remaining part of the carbon dioxide introduced betweenthe combustor casing 70 and the cylinder body 80 from the pipe 44 flowsthrough an annular space between the combustor casing 70 and thecylinder body 80 to the downstream side. At this time, similarly to thefirst embodiment, the carbon dioxide cools the combustor casing 70, thecylinder body 80 and the pipe-shaped member 101 of the ignition device110B.

According to the combustor 20B of the second embodiment as describedabove, including the contact prevention mechanism 104B makes it possibleto prevent the contact between the heat-resistant glass 102 included inthe pipe-shaped member 101 of the ignition device 100B and thecombustion gas. Therefore, the impurities such as soot do not adhere tothe inner surface 102 a of the heat-resistant glass 102. This preventsthe reduction in transmittance of the laser light 110 passing throughthe heat-resistant glass 102, resulting in enabling stable ignition.

Third Embodiment

FIG. 7 is an enlarged view schematically illustrating a longitudinalsection of an ignition device 100C in a combustor 20C of a thirdembodiment.

The combustor 20C of the third embodiment has the same configuration asthat of the combustor 20A of the first embodiment except a configurationof a contact prevention mechanism 104C of the ignition device 100C.Therefore, the configuration of the contact prevention mechanism 104C ismainly described here.

As illustrated in FIG. 7 , the ignition device 100C includes apipe-shaped member 101, a heat-resistant glass 102, a laser light supplymechanism 103, and the contact prevention mechanism 104C.

The contact prevention mechanism 104C prevents a combustion gas in acombustor liner 61 from coming into contact with the heat-resistantglass 102. The contact prevention mechanism 104C includes an annulargroove 160, a flow path 161, a fluid supply part 170 and an ejectionpart 180.

The annular groove 160 is formed around a periphery of the pipe-shapedmember 101 in a combustor casing 70 (for example, a downstream-sidecasing 72) through which the pipe-shaped member 101 penetrates. Theannular groove 160 is formed on a side closer to a combustor liner 61from the heat-resistant glass 102 in the combustor casing 70.

The flow path 161 is a flow path coupling the outside of the combustorcasing 70 and the annular groove 160. The flow path 161 is constitutedby a through hole penetrating from a side surface of the combustorcasing 70 to the annular groove 160.

The fluid supply part 170 supplies a contact prevention fluid to theflow path 161. Specifically, the fluid supply part 170 is coupled to theflow path 161.

Here, the fluid supply part 170 may be constituted by a pipe branchingoff from the pipe 42 which circulates the carbon dioxide heated in theheat exchanger 24 between the combustor liner 61 and the cylinder body80 (refer to FIG. 1 ), for example.

Further, the fluid supply part 170 may be constituted by a pipebranching off from the pipe 44 which circulates the carbon dioxidepressurized by the compressor 28 between the combustor casing 70 and thecylinder body 80 (refer to FIG. 1 ), for example.

Here, when the fluid supply part 170 is constituted by each of the pipesbranching off from the system of the gas turbine facility 10 asdescribed above, a filter (not illustrated) is preferably interposed inthe fluid supply part 170. Passing through the filter enables removal offoreign matter contained in a flow of the carbon dioxide. This makes itpossible to prevent the foreign matter from flowing into the combustorliner 61 and the turbine 25.

Moreover, the fluid supply part 170 may be a supply system (supply pipe)other than the system of the gas turbine facility 10, for example. Alsoin this case, the fluid supply part 170 supplies carbon dioxide at asupercritical pressure as the contact prevention fluid to the flow path161.

Here, even in any of the above-described configurations, the fluidsupply part 170 supplies the contact prevention fluid to the flow path161 so that a pressure of the contact prevention fluid to be ejectedfrom the ejection part 180 into the pipe-shaped member 101 is higherthan a pressure in the combustor liner 61.

Incidentally, the fluid supply part 170 functions as a second fluidsupply part. Further, the contact prevention fluid to be supplied fromthe fluid supply part 170 functions as a second fluid.

The ejection part 180 ejects the contact prevention fluid supplied tothe annular groove 160 into the pipe-shaped member 101. The ejectionpart 180 has a plurality of ejection holes 181 formed in acircumferential direction of the pipe-shaped member 101.

The ejection part 180 is formed in the pipe-shaped member 101 in aposition formed with the annular groove 160, as illustrated in FIG. 7 .In other words, the ejection holes 181 are formed in the circumferentialdirection of the pipe-shaped member 101 in the position formed with theannular groove 160.

A shape and a disposition configuration of the ejection holes 181 arethe same as those of the ejection holes 131 of the first embodiment.Further, the ejection holes 181 each penetrate in a directionperpendicular to a center axis of the pipe-shaped member 101, forexample.

Incidentally, as exemplified by the first embodiment (refer to FIG. 4 ),the ejection holes 181 may each be formed to be inclined to an endportion 101 a side of the pipe-shaped member 101 relative to thedirection perpendicular to the center axis of the pipe-shaped member101. An effect obtained by the above is the same as the effect describedby the first embodiment.

Here, the pressure of the contact prevention fluid to be ejected intothe pipe-shaped member 101 is higher than the pressure in the combustorliner 61. Therefore, the combustion gas flowing into the pipe-shapedmember 101 does not pass through the ejection holes 181 to flow into theannular groove 160. In other words, the contact prevention fluid ejectedfrom the ejection holes 181 into the pipe-shaped member 101 flows intothe combustor liner 61.

Next, the operation of the combustor 20C is described.

Here, the operation of the contact prevention mechanism 104C isdescribed.

The contact prevention fluid supplied from the fluid supply part 170 tothe annular groove 160 expands in the circumferential direction in theannular groove 160. The contact prevention fluid expanded in thecircumferential direction in the annular groove 160 is ejected throughthe ejection holes 181 of the pipe-shaped member 101 into thepipe-shaped member 101. Note that in FIG. 7 , flows of the contactprevention fluid ejected from the ejection holes 181 are indicated byarrows. Further, a flow rate of the contact prevention fluid ejectedfrom each of the ejection holes 181 is nearly uniform. Here, forexample, fixing an end portion 101 b on an outer side of the pipe-shapedmember 101 to the combustor casing 70 by welding prevents the contactprevention fluid introduced to the annular groove 160 from leakingoutside the combustor casing 70.

The flows of the carbon dioxide (contact prevention fluid) ejected fromthe ejection holes 181 are similar to the flows of the carbon dioxide(contact prevention fluid) ejected from the ejection holes 131 in thefirst embodiment. That is, the flows of the contact prevention fluidejected from the ejection holes 181 each travel in the directionperpendicular to the center axis of the pipe-shaped member 101, and atthe same time, turn to the combustor liner 61 side, as illustrated inFIG. 7 , for example.

Further, in the interior of the pipe-shaped member 101 being an innerside of the ejection holes 181, such a flow field as to shut off a crosssection of the interior of the pipe-shaped member 101 is formed by thecontact prevention fluid ejected from the plurality of ejection holes181 formed in the circumferential direction.

The flows formed by the contact prevention fluid ejected from theejection holes 181 prevent the combustion gas in the combustor liner 61from flowing into the pipe-shaped member 101. Alternatively, the flowsformed by the contact prevention fluid ejected from the ejection holes181 prevent the combustion gas flowing from the interior of thecombustor liner 61 into the pipe-shaped member 101 from flowing into theside closer to the heat-resistant glass 102 from positions formed withthe ejection holes 181.

This makes it possible to prevent the combustion gas in the combustorliner 61 from coming into contact with the heat-resistant glass 102 (aninner surface 102 a of the heat-resistant glass 102). Then, impuritiessuch as soot contained in the combustion gas do not adhere to the innersurface 102 a of the heat-resistant glass 102. Therefore, it is possibleto prevent a reduction in transmittance of the laser light 110 passingthrough the heat-resistant glass 102.

Incidentally, similarly to the first embodiment, a flow rate of thecontact prevention fluid to be ejected to the pipe-shaped member 101 canbe regulated by a hole diameter of the ejection hole 181 and the numberof the ejection holes 181. An effect obtained by the above is also thesame as that of the first embodiment.

According to the combustor 20C of the third embodiment as describedabove, including the contact prevention mechanism 104C makes it possibleto prevent the contact between the heat-resistant glass 102 included inthe pipe-shaped member 101 of the ignition device 100C and thecombustion gas. Therefore, the impurities such as soot do not adhere tothe inner surface 102 a of the heat-resistant glass 102. This preventsthe reduction in transmittance of the laser light 110 passing throughthe heat-resistant glass 102, resulting in enabling stable ignition.

Here, a configuration of the contact prevention mechanism 104C in thecombustor 20C is not limited to the above-described structure. FIG. 8 isan enlarged view schematically illustrating a longitudinal section ofthe ignition device 100C including another configuration in thecombustor 20C of the third embodiment.

As illustrated in FIG. 8 , the contact prevention mechanism 104C may beprovided outside the combustor casing 70.

In this case, the pipe-shaped member 101 is constituted by a cylindricalpipe having both ends thereof opened, or the like. The pipe-shapedmember 101 is provided to penetrate the combustor casing 70, thecylinder body 80 and the combustor liner 61.

Further, one end side of the pipe-shaped member 101 projects from thecombustor casing 70 to the outside. That is, the one end side of thepipe-shaped member 101 is extended to the outside of the combustorcasing 70. Note that in the pipe-shaped member 101, a portion projectingfrom the combustor casing 70 to the outside is referred to as an outsideprojecting portion 101 e.

Further, on an outer periphery of the outside projecting portion 101 eof the pipe-shaped member 101, for example, a flange 101 c is included.Then, attaching the flange 101 c on an outer surface of the combustorcasing 70 makes the pipe-shaped member 101 be fixed thereto.

The outside projecting portion 101 e is provided with the contactprevention mechanism 104C. Then, the heat-resistant glass 102 isdisposed in the pipe-shaped member 101 on a side closer to the outside(laser light supply mechanism 103 side) than a position provided withthe contact prevention mechanism 104C.

The contact prevention mechanism 104C includes an annular member 165, afluid supply part 170 and an ejection part 185.

The annular member 165 is provided on the outer periphery of the outsideprojecting portion 101 e over the circumferential direction, asillustrated in FIG. 8 . A cross-sectional shape perpendicular to thecircumferential direction in the annular member 165 is a U-shape. Then,the annular member 165 has a hollow portion. An open side (innerperipheral side) of the annular member 165 is joined to the outerperiphery of the outside projecting portion 101 e. By including theannular member 165 as described above, an annular passage 166 is formedon the outer periphery of the outside projecting portion 101 e.

Further, the annular member 165 is disposed between a position providedwith the flange 101 c and a position provided with the heat-resistantglass 102 in an axial direction of the pipe-shaped member 101.

The fluid supply part 170 supplies the contact prevention fluid to theannular passage 166. Specifically, the fluid supply part 170 isconnected to the annular member 165. Note that a pipe constituting thefluid supply part 170, or the like is as previously described.

The ejection part 185 ejects the contact prevention fluid supplied tothe annular passage 166 in the annular member 165 into the pipe-shapedmember 101. The ejection part 185 has a plurality of ejection holes 186formed in a circumferential direction of the outside projecting portion101 e.

The ejection holes 186 are formed in the pipe-shaped member 101 in aposition formed with the annular passage 166, as illustrated in FIG. 8 .In other words, the ejection holes 186 are formed in the circumferentialdirection of the outside projecting portion 101 e in the position formedwith the annular passage 166. A shape and a configuration of theejection holes 186 are the same as the previously-described shape andconfiguration of the ejection holes 181.

Here, the contact prevention fluid supplied from the fluid supply part170 to the annular passage 166 expands in the circumferential directionin the annular passage 166. Then, the contact prevention fluid expandedin the annular passage 166 is ejected from the ejection holes 186 intothe pipe-shaped member 101. Flows of the contact prevention fluidejected from the ejection holes 186 into the pipe-shaped member 101 aresimilar to the previously-described flows of the contact preventionfluid ejected from the ejection holes 181 into the pipe-shaped member101.

Incidentally, a pressure of the contact prevention fluid to be ejectedinto the pipe-shaped member 101 is higher than a pressure in thecombustor liner 61. Therefore, the combustion gas flowing into thepipe-shaped member 101 does not pass through the ejection holes 186 toflow into the annular passage 166. In other words, the contactprevention fluid ejected from the ejection holes 186 into thepipe-shaped member 101 flows into the combustor liner 61.

Fourth Embodiment

FIG. 9 is an enlarged view schematically illustrating a longitudinalsection of an ignition device 100D in a combustor 20D of a fourthembodiment.

The combustor 20D of the fourth embodiment has the same configuration asthat of the combustor 20A of the first embodiment except a configurationof a contact prevention mechanism 104D of the ignition device 100D.Therefore, the configuration of the contact prevention mechanism 104D ismainly described here.

As illustrated in FIG. 9 , the ignition device 100D includes apipe-shaped member 101, a heat-resistant glass 102, a laser light supplymechanism 103, and the contact prevention mechanism 104D.

The contact prevention mechanism 104D prevents a combustion gas in acombustor liner 61 from coming into contact with the heat-resistantglass 102. The contact prevention mechanism 104D includes an orificemember 190.

The orifice member 190 is constituted by a circular plate-shaped memberprovided in the pipe-shaped member 101. The orifice member 190 has athrough hole 191 which passes a laser light 110 through the centerthereof.

An outer periphery of the orifice member 190 is in contact with an innerperiphery of the pipe-shaped member 101. Such a configuration makes itpossible to prevent the combustion gas from flowing from between theouter periphery of the orifice member 190 and an inner surface of thepipe-shaped member 101 into the heat-resistant glass 102 side. Note thatan outer shape of the orifice member 190 is formed to correspond to ashape of an interior of the pipe-shaped member 101 in which the orificemember 190 is disposed.

A bore of the through hole 191 is set to a size to the extent that thelaser light 110 is not prevented from passing therethrough.

Here, one example of including the orifice member 190 in the pipe-shapedmember 101 between a combustor casing 70 and a cylinder body 80 isindicated, but this configuration is not restrictive.

For example, the orifice member 190 may be included in the pipe-shapedmember 101 between a combustor liner 61 and the cylinder body 80.

Here, since the laser light 110 is focused by a condensing lens 103 b, abeam diameter of the laser light 110 is reduced to a focal point 110 a.Therefore, including the orifice member 190 on the combustor liner 61side allows the bore of the through hole 191 to be smaller. This makesit possible to more securely suppress a flow of the combustion gasflowing through the through hole 191 into the heat-resistant glass 102side.

Next, the operation of the combustor 20D is described.

Here, the operation of the contact prevention mechanism 104D isdescribed.

At the time of ignition, the laser light 110 oscillated by a laseroscillator 103 a passes through the condensing lens 103 b, theheat-resistant glass 102, and the through hole 191 of the orifice member190 to enter the pipe-shaped member 101. The laser light 110 havingpassed through the interior of the pipe-shaped member 101 is focused onthe focal point 110 a in a predetermined region in the combustor liner61.

The inflow to the heat-resistant glass 102 side of the combustion gasflowing into the pipe-shaped member 101 is blocked by the orifice member190. Note that even though the combustion gas flows through the throughhole 191 to the heat-resistant glass 102 side, a flow amount thereof isa very small amount. Therefore, impurities such as soot do not adhere toan inner surface 102 a of the heat-resistant glass 102.

According to the combustor 20D of the fourth embodiment as describedabove, including the contact prevention mechanism 104D makes it possibleto suppress the contact between the heat-resistant glass 102 included inthe pipe-shaped member 101 of the ignition device 100D and thecombustion gas. Therefore, the impurities such as soot do not adhere tothe inner surface 102 a of the heat-resistant glass 102. This preventsthe reduction in transmittance of the laser light 110 passing throughthe heat-resistant glass 102, resulting in enabling stable ignition.

Here, a configuration of the combustor 20D of the fourth embodiment isnot limited to the above-described configuration.

For example, when the orifice member 190 is included in the pipe-shapedmember 101 between the combustor casing 70 and the cylinder body 80, thecontact prevention mechanism 104C of the third embodiment may be furtherincluded. Further, when the orifice member 190 is included in thepipe-shaped member 101 between the combustor casing 70 and the cylinderbody 80, the contact prevention mechanism 104B of the second embodimentmay be further included on the combustor casing 70 side of the orificemember 190.

For example, when the orifice member 190 is included in the pipe-shapedmember 101 between the combustor liner 61 and the cylinder body 80, thecontact prevention mechanism 104B of the second embodiment or thecontact prevention mechanism 104C of the third embodiment may be furtherincluded. Further, when the orifice member 190 is included in thepipe-shaped member 101 between the combustor liner 61 and the cylinderbody 80, the contact prevention mechanism 104A of the first embodimentmay be further included on the combustor casing 70 side of the orificemember 190.

In any of the cases, the contact prevention fluids ejected from theejection holes 131, 151, 181 of the contact prevention mechanisms 104A,104B, 104C into the pipe-shaped member 101 each flow through the throughhole 191 of the orifice member 190 to the combustor liner 61 side. Thismakes it possible to prevent the combustion gas from flowing through thethrough hole 191 to the heat-resistant glass 102 side.

Fifth Embodiment

FIG. 10 is an enlarged view schematically illustrating a longitudinalsection of an ignition device 100E in a combustor 20E of a fifthembodiment. Note that FIG. 10 illustrates a state where a shutoff valve200 is opened.

The combustor 20E of the fifth embodiment has the same configuration asthat of the combustor 20A of the first embodiment except a configurationof a contact prevention mechanism 104E of the ignition device 100E.Therefore, the configuration of the contact prevention mechanism 104E ismainly described here.

As illustrated in FIG. 10 , the ignition device 100E includes apipe-shaped member 101, a heat-resistant glass 102, a laser light supplymechanism 103, and the contact prevention mechanism 104E.

The pipe-shaped member 101 is constituted by a cylindrical pipe havingboth ends thereof opened, or the like. The pipe-shaped member 101 isprovided to penetrate a combustor casing 70, a cylinder body 80 and acombustor liner 61. Further, one end side of the pipe-shaped member 101projects from the combustor casing 70 to the outside. That is, the oneend side of the pipe-shaped member 101 is extended to the outside of thecombustor casing 70. Note that in the pipe-shaped member 101, a portionprojecting from the combustor casing 70 to the outside is referred to asan outside projecting portion 101 e.

Further, on an outer periphery of the outside projecting portion 101 eof the pipe-shaped member 101, for example, a flange 101 c is included.Then, attaching the flange 101 c on an outer surface of the combustorcasing 70 makes the pipe-shaped member 101 be fixed thereto.

The outside projecting portion 101 e is provided with the contactprevention mechanism 104E. Then, the heat-resistant glass 102 isdisposed in the pipe-shaped member 101 on a side closer to the outside(laser light supply mechanism 103 side) than a position provided withthe contact prevention mechanism 104E.

The contact prevention mechanism 104E prevents the combustion gas in thecombustor liner 61 from coming into contact with the heat-resistantglass 102. The contact prevention mechanism 104E includes the shutoffvalve 200.

The shutoff valve 200 is provided in a side portion of the outsideprojecting portion 101 e. The shutoff valve 200 is disposed between aposition provided with a flange 101 c and a position provided with theheat-resistant glass 12 in an axial position of the pipe-shaped member101. Then, the shutoff valve 200 communicates or shuts off a space 240 aon the heat-resistant glass 102 side in the pipe-shaped member 101 and aspace 240 b on the combustor liner 61 side in the pipe-shaped member101.

The shutoff valve 200 includes valve casings 210, 220 and a shutoffportion 230.

The valve casing 210 is constituted by a cylinder body having both endsthereof opened, or the like. As illustrated in FIG. 10 , one end 210 aof the valve casing 210 is fitted in and joined to an opening 101 dformed in a sidewall of the outside projecting portion 101 e. The otherend 210 b of the valve casing 210 has a flange 211, for example. Notethat the valve casing 210 may be formed integrally with the outsideprojecting portion 101 e.

The valve casing 220 is constituted by a cylinder body having both endsthereof opened, or the like. One end 220 a of the valve casing 220 has aflange 221, for example. One valve casing is constituted by fasteningthe flange 221 of the valve casing 220 and the flange 211 of the valvecasing 210 with a bolt, for example.

The shutoff portion 230 shuts off space in the pipe-shaped member 101.The shutoff portion 230 is provided to be movable forward and backwardin the valve casings 210, 220. For example, in a state where the shutoffportion 230 is closed, namely a closed state, the space 240 a and thespace 240 b are shut off. Here, in the closed state, the combustion gasflowing into the space 240 b does not flow to the space 240 a side.

A sealing member 250 such as packing is provided on an inner wall 220 bof the valve casing 220. The shutoff portion 230 moves while coming intocontact with the sealing member 250. Thus, the valve casing 220 and theshutoff portion 230 are sealed therebetween by the sealing member 250.

As the shutoff valve 200, for example, a needle valve, a ball valve, orthe like can be used. Note that the shutoff valve 200 is not limited tothese. As long as the shutoff valve 200 is a one which can shut off thespace 240 a and the space 240 b when the shutoff portion 230 is closed,the one can be used.

Next, the operation of the combustor 20E is described.

Here, the operation of the contact prevention mechanism 104E isdescribed.

At the time of ignition, the shutoff portion 230 is opened. Therefore, alaser light 110 oscillated by a laser oscillator 103 a passes through acondensing lens 103 b and the heat-resistant glass 102 to enter thepipe-shaped member 101. The laser light 110 having passed through theinterior of the pipe-shaped member 101 is focused on a focal point 110 ain a predetermined region in the combustor liner 61.

After confirming the ignition, the oscillation of the laser light 110 bythe laser oscillator 103 a is stopped, and at same time, the shutoffportion 230 is closed. This causes the space 240 a and the space 240 bto be shut off.

Therefore, the inflow to the heat-resistant glass 102 side of thecombustion gas flowing into the pipe-shaped member 101 is blocked by theshutoff portion 230. This causes impurities such as soot not to adhereto an inner surface 102 a of the heat-resistant glass 102.

According to the combustor 20E of the fifth embodiment as describedabove, including the contact prevention mechanism 104E makes it possibleto suppress the contact between the heat-resistant glass 102 included inthe pipe-shaped member 101 of the ignition device 100E and thecombustion gas. Therefore, the impurities such as soot do not adhere tothe inner surface 102 a of the heat-resistant glass 102. This preventsthe reduction in transmittance of the laser light 110 passing throughthe heat-resistant glass 102, resulting in enabling stable ignition.

According to the embodiments described above, it becomes possible toprevent the impurities such as soot from adhering to the heat-resistantglass of the laser ignition device and to perform stable ignition.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. A gas turbine combustor, comprising: a casing; a combustion cylinder which is provided in the casing and is configured to combust fuel and oxidant to produce combustion gas; a pipe-shaped member provided to penetrate the casing and the combustion cylinder; a heat-resistant glass which is provided on the casing side in the pipe-shaped member and disposed to close the pipe-shaped member; a laser light supply configured to irradiate an interior of the combustion cylinder through the heat-resistant glass and an interior of the pipe-shaped member with a laser light; and a contact prevention mechanism configured to prevent the combustion gas in the combustion cylinder from coming into contact with the heat-resistant glass, wherein the contact prevention mechanism comprises: an annular groove formed around a periphery of the pipe-shaped member in the casing through which the pipe-shaped member penetrates; a flow path which is formed in the casing and configured to guide a fluid to the annular groove; a fluid supply part configured to supply the fluid to the flow path; and an ejection part which has a plurality of ejection holes formed in a circumferential direction of the pipe-shaped member and is configured to eject the fluid supplied to the annular groove through the ejection holes into the pipe-shaped member.
 2. A gas turbine combustor, comprising: a casing; a combustion cylinder which is provided in the casing and is configured to combust fuel and oxidant to produce combustion gas; a pipe-shaped member provided to penetrate the casing and the combustion cylinder; a heat-resistant glass which is provided on the casing side in the pipe-shaped member and disposed to close the pipe-shaped member; a laser light supply configured to irradiate an interior of the combustion cylinder through the heat-resistant glass and an interior of the pipe-shaped member with a laser light; and a contact prevention mechanism configured to prevent the combustion gas in the combustion cylinder from coming into contact with the heat-resistant glass, wherein the pipe-shaped member has an outside projecting portion projecting to an outside of the casing; and the contact prevention mechanism comprises: an annular member which is provided on an outer periphery of the outside projecting portion over a circumferential direction and includes an annular passage; a fluid supply part configured to supply a fluid to the annular passage; and an ejection part which has a plurality of ejection holes formed in a circumferential direction of the outside projecting portion and is configured to eject the fluid supplied to the annular passage through the ejection holes into the pipe-shaped member.
 3. The gas turbine combustor according to claim 1, wherein the fluid is a combustion gas discharged from the combustion cylinder to drive a turbine.
 4. The gas turbine combustor according to claim 2, wherein the fluid is a combustion gas discharged from the combustion cylinder to drive a turbine. 